This invention relates to a packing apparatus for traveling a band along a band way while keeping a packed object or package stationary on a fixed member such as a table or the like and drawing out the band from the band way to tightly wind it around the package, and more particularly to a flap construction of a band guide arch structure in such a packing apparatus.
A conventional packing apparatus is generally constructed in such a manner as shown in FIGS. 1 to 7. More particularly, the conventional packing apparatus, as shown in FIG. 1, includes a body 1, on which a pair of tables 2 and 3 are fixedly mounted. The tables 2 and 3 are arranged so as to be horizontally spaced from each other at a predetermined interval, resulting in being a band passage 4 being defined therebetween. On the tables 2 and 3 is arranged a band guide arch structure 5 of a substantially inverted U-shape in a manner to extend between both ends of the tables 2 and 3 and straddle the band passage 4.
The band guide arch structure 5, as shown in FIG. 2, a central arch frame 6 and arch covers 7a and 7b arranged so as to interpose the arch frame 6 therebetween. The arch frame 6 is provided on an inner side or inner periphery thereof with a band way 8, so that a band B may travel on a surface of the band way.
The arch frame 6, as shown in FIG. 3, is mounted thereon through a plurality of support members 10 with flaps 11 and 12. The flaps 11 and 12, as shown in FIG. 2, each are formed into an L-shape in cross section and fixedly mounted at one end thereof with a member including at least a pair of support elements 13 in a manner to be integral therewith. The support elements 13 each are formed with a through-hole 14.
The flaps 11 each are formed into a straight or linear shape and arranged on each of straight or linear sections of the arch frame 6 and the flaps 12 each are formed into a curved shape and arranged on each of corner sections of the arch frame 6.
The support members 10 each are formed into a substantially flat U-shape, resulting in being proved at both ends thereof with lugs 15 and mounted a bottom portion thereof on the arch frame 6. The lugs 15 each are formed with a through-hole 16 and a small through-hole 17. Each of the support members 10 is fixed on a side surface of the arch frame 6. The flaps 11 and 12 each are mounted on the support member 10 by fitting the support elements 13 in the support member 10 while aligning the through-holes 14 of the support elements 13 with the through-holes 16 of the lugs 15. Then, a support shaft 19 having a spring 18 wound thereon is inserted through the aligned holes 14 and 16, to thereby mount each of the flaps 11 and 12 through each of the support members 10 on the arch frame 6. The spring 18, as shown in FIG. 3, is provided at a central portion thereof with a U-shaped presser portion 20, through which the spring 18 is divided into two sections, which are wound in directions opposite to each other. Also, a shaft 21 is heldly inserted through the small through-holes 17 of each of the support members 10 to hold both ends of the spring 18, as shown in FIG. 3.
The spring 18 acts to restrain each of the flaps 11 and 12 through the presser portion 20 of the spring 18. Also, the flaps 11 and 12 each are arranged so as to be pivotally moved in a direction indicated at an arrow in FIG. 3 from a position shown in FIG. 3, however, it is not pivotally moved in a direction opposite to the direction of the arrow because each of the support element 13 is abutted at a proximal portion thereof against the support member 10. This permits each of the flaps 11 and 12 and the band way 8 to be normally spaced in parallel from each other at a predetermined interval, to thereby define a space therebetween, as shown in FIG. 3, so that the band B may travel in the space thus defined.
When force is applied to each of the flaps from the side of the band way 8, elastic force of the spring 18 causes the flap to be pivotally moved in a direction of application of the above-described force from the band way 8, so that the flap is rendered open to expose the band way 8. Thus, it will be noted that each of the flaps 11 and 12 is openable about the support shaft 19 with respect to the band way 8.
Reference numeral 6a in FIG. 3 designates a band guide plate. The band guide plate 6a is arranged on a side of the arch frame 6 opposite to a side thereof on which the support member 10 is provided and acts to prevent the band B traveling along the band way 8 from being dislocated from the band way 8.
Now, an internal structure of the body 1 will be described hereinafter.
The body 1, as shown in FIG. 1, is mounted thereon with an upper presser plate 9 in a manner to be reciprocated in a direction perpendicular to a band travel path of which at least a part is defined by the band passage 4. For this purpose, the upper presser plate 9 is constructed so as to retractably project in the direction traversing or perpendicular to the band travel path. Also, the body 1, as shown in FIG. 4, is provided therein with a band guide 22 for guiding the band B to the band way 8. The band guide 22 is constructed so as to retractably project toward the band travel path as in the upper presser plate 9. The band guide 22 is formed into a substantially U-shape in section and provided therein with a guide groove 23, through which the band B is guided to the band way 8 while being received in the guide groove 23. Further, the band guide 22 is provided on an upper surface thereof with a stopper 24, which comprises a projection formed by upwardly projecting the upper surface of the band guide 22 and provided so as to be contacted with a lower surface of the upper presser plate 9. The stopper 24 is arranged so as to ensure a sufficient distance between the stopper 24 and a band inlet 23a of the guide groove 23 in a horizontal direction. More particularly, the stopper 24 is positioned in proximity to a band outlet 23b of the guide groove 23 rather than the band inlet 23a.
In addition, the body 1, as shown in FIG. 6, includes a right-hand presser member 25, a left-hand presser member 26, a heater 27, a press member 28, and a lower blade 29 integrally mounted on the press member 28. These members cooperate with each other to construct a sealing mechanism.
The right-hand presser member 25 is positioned on an upstream side in a direction of travel of the band B based on the band inlet 23a of the band guide 22 as shown in FIG. 4 and arranged in a manner to be vertically movable. The right-hand presser member 25 is formed with a guide hole 30. The guide hole 30 has an outlet defined on a downstream side in the direction of travel of the band B. The outlet serves as an upper blade 31, which cooperates with the above-described lower blade 29 to constitute a cutter mechanism. Also, the right-hand presser member 25 is provided on an upper end thereof with a non-slip portion 25a, which is arranged so as to be pressedly contacted with the lower surface of the upper presser plate 9 when the right-hand presser member 25 is raised to an uppermost position. The non-slip portion 25a and upper presser plate 9 cooperate with each other to provide a holding mechanism for interposedly holding a distal portion of the band B therebetween.
The left-hand presser member 26 is arranged below the upper presser plate 9 and at a position opposite to the band outlet 23b of the guide groove 23 of the band guide 22 in a manner to be slidable in a vertical direction. Also, the left-hand presser member 26 is provided at an upper end thereof with a non-slip portion 26a. The left-hand presser member 26 thus constructed is raised after the band guide 22 is retracted from the band travel path, so that the non-slip portion 26a of the presser member 26 may be pressedly contacted with the lower surface of the upper presser plate 9, resulting in the band B being interposedly held between the non-slip portion 26a of the presser member 26 and the lower surface of the upper presser plate 9.
The heater 27 is arranged in a manner to be retractably positioned with respect to the band travel path, to thereby be selectively positioned in or out of the band travel path.
The press member 28 is likewise arranged below the upper presser plate 9 and at a position opposite to the band inlet 23a of the guide groove 23 of the band guide 22 in a manner to be movable in the vertical direction. The press member 28 is integrally mounted thereon with the lower blade 9 and raised after the band guide 22 is retracted from the band travel path.
Further, the body 2, as shown in FIG. 4, is provided therein with a feed roller 32 and an upper roller 33, which are arranged outside the right-hand presser member 25. The feed roller 32 and upper roller 33 cooperate with each other to constitute a band delivery mechanism. On the outside of the rollers 32 and 33 is arranged a tension arm 34 as shown in FIG. 6, which is provided with a passage 35 through which the band B is passed, a tension jaw 37 pivotally moved about a pin 36, and a presser member 38 for forcibly pivotally moving the tension jaw 37 in a clockwise direction in FIG. 6.
The tension arm 34, tension jaw 37 and presser member 38 cooperate with each other to provide a tension mechanism.
Now, the manner of operation of the conventional packing apparatus constructed as described above will be described hereinafter with reference to FIGS. 4 to 7 as well as FIG. 1.
First, a package W is put on the tables 2 and 3 so as to be positioned below the band guide arch structure 5 as shown in FIG. 4. Then, the band guide 22 is kept at a raised position and the guide hole 30 of the right-hand presser member 25 is positioned so as to be opposite to or aligned with the guide groove 23 of the band guide 22. Subsequently, the band wound on a reel 39 is drawn out through a pool box from the reel 39 and then inserted into the guide hole 30 of the right-hand presser member 25 and the guide groove 23 of the band guide 22 through the tension mechanism and band delivery mechanism.
Then, the feed roller 32 constituting a part of the band delivery mechanism is rotated in a direction indicated at an arrow in FIG. 4, so that the band B is permitted to travel at a high speed along the band way 8 in the band guide arch mechanism 5, resulting in a distal end of the band B coming into collision with the stopper 24 of the band guide 22.
Subsequently, the right-hand presser member 25 is further raised as shown in FIG. 5, so that the band B is interposedly held between the non-slip portion 25a of the right-hand presser member 25 and the upper presser plate 9. Then, the band guide 22 is retracted from the band travel path.
Thereafter, the feed roller 32 is reversely rotated in a direction indicated at an arrow in FIG. 5, to thereby pull the band B in a direction indicated at an arrow in FIG. 5, resulting n tension being applied to the band B. This causes pull-back force to be applied to the band B, so that the band B arranged in a loop-like manner in the gap between the band way 8 and each of the flaps 11 and 12 forcedly opens the flap, to thereby be drawn out of the gap between the band way 8 and the flap. This results in the band B being tightly wound on the package W as shown in FIG. 5.
Then, the tension Jaw 37 is pivotally moved in the clockwise direction while being forced by the presser member 38 of the tension mechanism, so that the band B may be firmly held. Then, the tension arm 34 is rotated in a direction indicated at an arrow in FIG. 6, to thereby further pull the band B. After the band B is thus pulled, the left-hand presser member 26 is raised to an uppermost position to interposedly hold the band B between the non-slip portion 26a of the left-hand presser member 26 and the upper presser plate 9. In this state, the band B is so arranged that the above-described distal portion of the band B defined on the basis of a direction of delivery of the band is kept vertically spaced from a proximal portion of the band positioned between the right-hand presser member 25 and the left-hand presser member 26, resulting in a gap being defined between the distal portion and the proximal portion as shown in FIG. 6. Then, the heater 27 is inserted into the gap thus formed. In addition, the press member 28 is upwardly moved, resulting in the lower blade 29 mounted on the press member 28 being likewise raised, so that the lower blade 29 cooperates with the upper blade 31 formed by the inlet of the guide hole 30 to cut the band B. Concurrently, the heater 27 melts the distal and proximal portions of the band B between which the heater is inserted. Then, the press member 28 is downwardly moved and the heater 27 is retracted.
Subsequently, the press member 28 raised again as shown in FIG. 7, so that the melted distal and proximal portions of the band B are adhered to each other. Finally, the left-hand presser member 26 and press member 28 are lowered and the upper presser plate 9 is retracted, so that the band B is firmly wound on the package W while being tightly contacted therewith.
Unfortunately, it was found that the conventional packing apparatus constructed as described above exhibits some disadvantages.
More particularly, the draw-back force applied to the band B as described above causes the band B to forcedly open each of the flaps 11 and 12, resulting in the band B being drawn out from the gap between each of the flaps 11 and 12 and the band way 8. At this time, a failure in adjustment of force by which each of the curved flaps 12 arranged at the corner sections is pivotally moved causes the band B to be drawn out from the flap 12 at each of the corner sections of the arch frame 6 of the band arch guide structure 5 concurrently or irregularly. For example, when elastic force of the spring 18 of each of the curved flaps 12 at the corner sections is smaller than the draw-back force of the band B, the band B is caused to be drawn out from any one of the curved flaps 12 at the corner sections before it is drawn out in order from an inlet end side of the band guide arch structure 5 toward an outlet end side thereof. Alternatively, when elastic force of the spring 18 is excessively large, drawing-out of the band B from the curved flap 12 at each of the corner sections is rendered highly difficult. Thus, drawing-out of the band B from each of the flaps 12 at the corner sections is lastly carried out, so that drawing-out of the band B from the flaps 11 and 12 is rendered irregular.
Unfortunately, such irregular drawing-out of the band B from the flaps causes a failure in uniform winding of the band B around the package W, leading to troubles such as slack of the band B, twist thereof and the like.
Also, the drawing-out of the band B from the flaps is carried out in order of O.fwdarw.P.fwdarw.Q.fwdarw.R in the clockwise direction as shown in FIG. 1, resulting in adjustment of the springs 18 being required in correspondence to operation of the flaps at the straight sections and corner sections and depending on order of drawing-back of the band from the flaps at the corner sections.
It is required to increase a degree at which the flaps 12 at the corner sections O, P, Q and R are open by an amount corresponding to bending of the flaps 12 as compared with the flaps 11 at the straight sections. Otherwise, drawing-out of the band from the flaps 12 at the corner sections is failed. This requires an increase in angle at which the flaps at the corner sections O, P, Q and R are pivotally moved. Unfortunately, an increase in angle of pivotal movement of the flaps 12 causes the flaps to be contacted with the arch frame 6 of the band guide arch structure 5 when the flaps 12 are returned to the original position, resulting in noise or contact sound being produced.
Thus, the conventional packing apparatus causes a considerable amount of load to be applied to each of the springs 18 at the corner sections of the arch frame 6, therefore, fine adjustment of the spring 18 described above which is highly troublesome must be carried out while paying attention to durability of the spring.